Tool rest for grinding machines



June 5, 1951 H. T. SCOTT TOOL REST FOR GRINDING MACHINES Filed Oct. 6,1947 INVENTOR. /2/ HAQQY 7. 56077 4 TTD/2N E Y (f/ MM Patented June 5,1951 ASTATES `PAT EN T OFFICE TOOL REST FOR GRIND'ING MACHINES Harry T.Scott, Los Angeles, Calif.

Application Gotober 6, 1947, Serial N o. 778,180

SClams. l

This invention relates generally to tool grinding machines, and `moreparticularly to tool rests therefor.

An object o f this invention is to provide a tool rest which isstructurally characterized in a manner to enable it to be readilyapplied to grinding machines at present being manufactured; which isparticularly adapted for low cost production by modern, efficient andeconomical precision die cast methods; which is angularly adjustableabout afixed Yaxis preferably in close proximity to the peripheral faceof the grinding wheel and hence parallel to the axis of the grindingwheel, whereby to enable a tool bit to be hollow ground by using the`periphery of the wheel and thus reduce to a minimum the stoning of thebit required to produce a smooth, clean and sharp cutting edge.

Another .object of this invention is to provide a tool rest of the abovedescribed character whose fixed axis about which angular adjustment ofthe rest is effected, obviates any shifting of the rest towards or awayfrom the grinding wheel, so as to insure proper relationship between thetool being ground and the grinding wheel, irrespective of angularadjustment `of the tool rest, all while maintaining the table of thetool rest free of projections which would interfere with the freemanipulation `of the tool bit on the table.

A further object of this invention is to provide a tool rest, the tableof which is suitably scribed or marked to guide the operator in grindinga tool bit to a predetermined angle; `whose table, when of die `castmetal, is provided with ahard metal insert to effectively resist thewear and tear to which the table is subjected by the tool bits; which,for angular adjustment of the table, i provided with journals `of `suchconstruction that the rest can be made relatively compact so as to ntinto a small space; and which is adapted to be angularly adjusted .aboutthe axis of the journals and securely locked in a selected position vofadjustment with the utmost ease and dispatch.

With these and other objects in View, this invention resides in thecombinations, arrangements and functional relationships of elements asset forth in the following specification and particularly pointed out inthe appended claims.

In the accompanying drawings,

`Figure l is a plan View of the tool rest for grinding machinesembodying this invention;

Figure 2 is a vertical sectional View of the tool` rest taken on theline 2-2 of Figure l;

`Figure 3 is a :vertical sectional View of the tool rest mounted on aconventional grinding machine, and taken on the line 3-3 of Figure 1;

Figure 4 is a vertical sectional view taken on the line ll--li of Figure2;

Figure 5 is a Vertical sectional view taken on the line oi Figure l; andFigure G1 is a `View oi the tool rest in left side elevation.

Referring specifically to the drawings, this invention in `itsillustrated embodiment, broadly comprises a base E anda table T mountedthereon for adjustment about a fixed axis a, the base and table beingpreferably die -cast of `suitable metal. The base is formed to provide afiat bottom lli, side walls 1I, and a back wall I2, the central portionof which latter is inwardly offset to define `a recess I3 whose widthclosely receives the peripheral portion of the grinding wheel G of `aconventional grinding machine having a very elementary form ofadjustable tool rest R. By means of two cap screws or bolts Ii passingfreely through openings in the bottom li of the Vbase B, the latter maybe rigidly secured on the top plate i5 of the rest R by screwing thescrews lli into bores if which are suitably drilled and tapped in theplate.

The table T comprises a fiat rest plate 2G from which subtends sidewalls 21 and aback wall 22 within which the base B is received as shownin Figures 2, 4 and 5. The back .edge of ,the rest plate ZB is providedwith a recess 23 corresponding to the recess i3 of the base B so as toreceive the peripheral portion of the grinding wheel G. The rest plate2li is further provided with a recess 2d extending from one side of therest plate to `the other `and receiving a wear plate 25 of relativelyhard metal whose top surface is flush with the surface of the restplate. The wear plate is rigidly secured to the rest plate by screws 26,with the rear top edge of `the wear plate coinciding with the `firedaxis a.

The fixed axis u is formed by segmental trunnions or journals Si!! onthe inner sides of the walls 2|, which seat in segmental bearings ilformed on the side walls il of the base As illustrative of one means formaintaining the journals 3l! against upward displacement from the`nee-rings 3i, coil springs 32 are connected under tension to anchorpins i3 and 34 seating in recesses inthe rest plate 2li of the table andin the bottom iii of the base, respectively, as shown in Figure 5, so asto hold the trunnions in contact with the bearings, yet permit freeangular adjustment of the table on the base about the aX-is a.

Other bearings 4l] are provided on the side walls Il of the base B torotatably mount a shaft 4| whose ends'project through arcuate slots 42and 43 in the side walls 2i of the top T. Fixed to one end of the shaft4| by a set screw 44, is an actuating member orknob 45 whose hub isformed to provide a driving gear 46 projecting into the slot 42 andconstantly meshing with curved rack teeth or segmental rack 41 on onewall of the slot. Thus, upon rotating the member 45 in the l0 clockwisedirection of the arrow in Figure 6, the gear 46 will co-act with therack 4l to angularly adjust the table T about the axis a from the fullline position in Figure 8 towards the broken line position in thisfigure. 15

The other end of the shaft 4I is threaded at 48 to receive a clamp nut49 in the form of a lever by which the table T can be clamped to thebase B in any selected position of angular adjustment, by simplytightening the nut. The front of the o table T is closed by a curvedcover or name plate '5U whose lower edge is curled inwardly as indicatedat I to provide a finger grip adapted to be grasped by the operator toeffect a quick, rough adjustment of the table. .25

The periphery of the actuating member 45, which is provided with a dialhaving graduations 60 numbered in degrees of angles, is of suchcurvature that the periphery will remain in tangential relationship tothe top surface of the rest plate irrespective of the position ofadjustment of the table, for co-action with a fixed graduation 6I on therest plate (Figure l) in indicating the angle to which the table T isadjusted.

The top of the rest plate 20 is provided with Y angle indicating lines62 and appropriate indicia for indicating tool angles, and is furtherprovidedwith lines 63 and appropriate indicia for indicating back rake,all in the operation of the invention which is as follows:

With the tool rest embodying this invention applied to the grindingmachine as shown in Figure 3, the top surface of the rest plate 20 ishorizontally disposed at the level of the axis of the grinding wheel G,and the iixed axis a is in close proximity to the peripheral surface ofthe grinding' wheel and parallel to the axis of the latter, to thuslocate the table T symmetrically about the peripheral portion of thegrinding wheel for use of the periphery of the wheel in the hollowgrindo ing of tool bits, as well as the sides of the wheel for variousother grinding operations upon the bits.

The table T is now adjusted by rotating the member 45, and is thenlocked in a selected position by the nut 49, for grinding of apredetermined front or side clearance upon the tool bity when placed onthe rest plate ZIJ and fed over the hard wear plate against theperiphery of the grinding wheel. A predetermined tool angle or back rakemay be accurately ground on the toolI bit by utilizing the correspondingangle indicating line B2 or 63 as a guide in feeding the bit to thewheel.

, I claim:

1. A tool rest for grinding machines comprising: a base adapted to berigidly mounted on a support of the grinding machine; a table; said baseand table having means co-acting to provide 7 a xed axis in closeproximity to a surface of said wheel, forangular adjustment of the tablerelative to the base; a shaft journaled on said base about an axis inspaced parallel relationship to .saidxed axis; means on the shaft andtable 7 co-acting to angularly adjust the table about said fixed axis inresponse to rotation of said shaft; an actuating member fixed to theshaft and having a dial graduated in degrees of angles for coaction witha fixed graduation on the table in indicating the positions of angularadjustment of the table; and means for releasably retaining the table inselected positions of adjustment.

2. A tool rest for grinding machines comprising: a base adapted to berigidly mounted on a support of the grinding machine; a table having aiiat work supporting surface; said base and table having means co-actingto provide a fixed axis in close proximity to a surface of said wheel,for

. angular adjustment of the table relative to the base; a shaftjournaled on said base about an axis in spaced parallel relation to saidfixed axis; means on the shaft and table co-acting to angularly adjustthe table about nsaid iixed axis in response to rotation of said shaft;a member iixed to said shaft at a location beyond one end of said tableand having a peripheral dial graduated in degrees of angles foralinement with a fixed graduation on said work supporting surface of thetable in indicating the position of angular adjustment of the table;vthe peripheral contour of said member being such as to maintain atangential relationship between the peripheral surface of said memberand said work supporting surface of the table at said fixed graduationthereof, irrespective of the position of adjustment of the table.

3. A tool rest forgrinding machines comprising: a base adapted to berigidly mounted on a support of the grinding machine; a table having afiat rest plate and arcuately slotted sidewalls subtending therefrom atopposite sides of the base; the table having alined, downwardly facingsegmental journals beneath said rest plate, whose centers are coincidentto the top surface of the. plate; the base having upwardly open,segmental bearings in which said journals are seated to mount the tablefor angular adjustment relativel to the base; a shaft rotatably mountedon said base parallel to the axis of said journals and projectingthrough said slots of said side walls; a gear fixed to said shaft; asegmental rack iixed to said table ,and with which said gear meshes, toangularly adjust the table about said fixed axis in response to rotationof the shaft; a member fixed to one projecting end of said shaft andhaving a dial graduated in degrees of angles for co-action with a fixedgraduation on said rest plate, in indicating the position of angularadjustment of the table; and means at the other projecting end of saidshaft, co-acting with said member to releasably retain the table in aselected position of adjustment.

4. A tool rest for grinding machines comprising: a base adapted to berigidly mounted on a support of the grinding machine; a table having aflat rest plate and arcuately slotted sidewalls subtending therefrom atopposite sides of the base; the table having alined, downwardly facingsegmental journals beneath said rest plate, whose centers are coincidentto the top surface of the rest plate; the base having upwardly open,segmental bearings in which said journals are seated to mount the tablefor angular adjustment rela` tive to the base; a shaft rotatably mountedon said base parallel to the axis of said journals and 0 projectingthrough said slots of said side walls;

a gear ilxed to said shaft; a segmental rack formed in one of said slotsand with which said gear meshesto angularly adjust the table about saidiixed axis in response to rotation of the shaft; an actuating knob iixedtorone end of said'shaft exteriorly of one side wall of said table andhaving a dial graduated in degrees of angles for coaction with a fixedgraduation on said rest plate, in indicating the position of angularadjustment of the table; and a locking knob threadedly mounted on theother end of said shaft exteriorly of the other side wall of said tablefor co-action of said knobs with the respective side walls in bindingsame against the base when the locking knob is tightened, whereby toreleasably retain the table in a selected position of adjustment.

5. A tool rest for grinding machines comprising: a base adapted to berigidly mounted on a support of the grinding machine; a table having aflat rest plate and arcuately slotted sidewalls subtending therefrom atopposite sides of the base; the table having alined, downwardly facingsegmental journals beneath said rest plate, whose centers are coincidentto the top surface of the rest plate; the base having upwardly open,segmental bearings in which said journals are seated to mount the tablefor angular adjustment relative to the base; a shaft rotatably mountedcn said base parallel to the axis of said journals and projectingthrough said slots of said side walls; a gear xed to said shaft; asegmental rack xed to said table and with which said gear meshes, toangularly adjust the table about said fixed axis in response to rotationof the shaft; an actuating knob fixed to one end of said shaftexteriorly of one side wall of said table and having a dial graduated indegrees of angles for coaction with a fixed graduation on said restplate, in indicating the position of angular adjustment of the table;and a locking knob threadedly mounted on the other end of said shaftexteriorly of the other side wall of said table for coaction of saidknobs with the respective side walls in binding same against the basewhen the locking knob is tightened, whereby to releasably retain thetable in a selected position of adjustment; said dial being arranged onthe peripheral surface of said actuating knob, whose contour is such asto maintain a tangential relationship between said surface and said restplate at the fixed graduation thereon, irrespective of the position ofadjustment of the table.

6. A tool rest for grinding machines as embodied in claim 5, whereinsaid table is provided with a finger grip along the front thereof,adapted to be gripped to effect a rough adjustment of the table; andsaid rest plate is provided with a relatively hard metal insertremovably fitted in a recess in close proximity to the grinding surfaceof the grinding wheel and flush with the top surface of the rest plate.

7. A grinding machine having a grinding wheel and a tool rest support; abase rigidly mounted on said support at the periphery of the grindingwheel; a table having a fiat Work supporting surface; said base havingalined, upwardly open segmental bearings whose centers define a fixedaxis co-incident and parallel to said surface of said table and inparallel relationship to the periphery of the grinding wheel in closeproximity thereto; the table having segmental journals mounted in saidbearings for angular adjustment of the table on the base about saidfixed axis; and spring means operatively connected to said base andtable to yieldingly maintain said journals in working engagement withsaid bearings against displacing forces incident to a tool grindingoperation, yet render the table readily adjustable angularly on the baseas aforestated; and means for releasably retaining the table in selectedpo sitions of adjustment.

8. A tool rest for grinding machines comprising: a base adapted to berigidly mounted on a support of the grinding machine; a table; said baseand table having means co-acting to provide a fixed axis in closeproximity to the periphery of said wheel; a shaft journaled on said baseabout an axis in spaced parallelism to said fixed axis; a member xed tosaid shaft and having a dial graduated to co-act with a xed graduationon the table in indicating positions of angular adjustment of the table;said table being adapted to be grasped and manually moved directly aboutsaidL xed axis to effect a quick angular adjustment of the table; andmeans on said shaft and table co-acting to rotate the shaft inaccordance with the aforesaid manual movement of the table, forco-action of said member graduations with said table graduation inindicating the position to which the table is moved.

HARRY T. SCOTT.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 134,296 Libbey Dec. 24, 1872565,644 Taylor Aug. 11, 1896 876,372 Matthews Jan. 14, 1908 957,978Meyers May 17, 1910 1,259,494 Downer 1 Mar. 19, 1918 1,277,377 CarterSept. 3, 1918 2,176,726 Shepherd Oct. 17, 1939 2,374,716 Wiken May 1,1945

